You need to be playing against 3 or more players. That way, when you’re dealing your cards you just have to beat more players than beat you. For example if you’re playing 5 ppl, you just need to beat 3 and payout on 2.

I used to deal BJ in casinos, and the swings are unpredictable and dramatic. You’ve already received some good advice in making sure you stick to single deck rules if your dealing single deck. Also, shuffle before you get to low in the deck.

The other thing i’d recommend is watch out for your friends that raise their bets up towards the end of the deck. They might be smart enough to be tracking 10’s and aces, and know they have a higher chance of getting a blackjack, and are raising their bets accordingly. This is what gives card counters an advantage, and is frowned upon and monitored by casino management.

BJ is a game played and loved by many because the odds are so close to being in the players favor. Worst games are only ~3.6% in favor of the house, and best are ~1%. So of course your swings can be huge….. see link below for more on odds.